Resource allocation method and a method for transmitting/receiving resource allocation information in mobile communication system

ABSTRACT

According to one embodiment, a user equipment for use in a mobile communication system is configured to: receive control information including a first field and a second field via a control channel, the first field indicating one of N (N≧2) resource block group (RBG) sets and the second field including a bitmap, wherein each bit of the bitmap is used to indicate whether a corresponding resource block (RB) in the indicated one of the N RBG sets is allocated; interpret the first field and the second field for resource allocation in the control information; and receive data using the control information. An RBG set n (0≦n&lt;N) includes every N th  RBG starting from n th  RBG, an RBG includes one or more consecutive RBs, and an RB includes a plurality of consecutive subcarriers.

TECHNICAL FIELD

The present invention relates to a mobile communication system, and moreparticularly to a resource allocation method and a method fortransmitting/receiving resource allocation information in a mobilecommunication system.

BACKGROUND ART

In a mobile communication system, a scheduling method for datatransmission, that is, a resource allocation method is divided into afrequency diversity scheduling (FDS) method for obtaining a receptioncapability gain using frequency diversity and a frequency selectivescheduling (FSS) method for obtaining a reception capability gain usingfrequency selective scheduling.

In the FDS method, a transmitter transmits a data packet viasubcarriers, which are widely distributed in a system frequency domain,such that symbols within the data packet are subjected to a variety ofradio channel fading. Accordingly, the whole data packet is preventedfrom being subjected to disadvantageous fading and thus receptioncapability is improved.

In contrast, in the FSS method, a data packet is transmitted via one ora plurality of consecutive frequency domains, which is in anadvantageous fading state, in a system frequency domain such thatreception capability is improved.

Actually, in a cellular OFDM radio packet communication system, aplurality of user equipments exist in a cell and radio channel states ofthe user equipments have different characteristics. Accordingly, even ina subframe, data transmission using the FDS method needs to be performedwith respect to any user equipment and data transmission using the FSSmethod needs to be performed with respect to the other user equipments.Accordingly, it is preferable that the FDS transmission method and theFSS transmission method are efficiently multiplexed in the subframe.

DISCLOSURE OF INVENTION

Accordingly, the present invention is directed to a resource allocationmethod and a method for transmitting/receiving resource allocationinformation in a mobile communication system that substantially obviateone or more problems due to limitations and disadvantages of the relatedart.

An object of the present invention devised to solve the problem lies onan efficient resource allocation method.

Another object of the present invention devised to solve the problemlies on a method for transmitting resource allocation informationaccording to an efficient resource allocation method.

The object of the present invention can be achieved by providing amethod for receiving resource allocation information in mobilecommunication system, the method including: receiving first informationwhich indicates a resource block group set and second information whichis a bitmap indicating whether or not to allocate resource blockincluded in the resource block group set via a control channel;identifying allocated resource block from the first information and thesecond information; and receiving data using the allocated resourceblock.

The first information may indicate one among one or more resource blockgroup set.

The resource block group set may include one or more resource blockgroup.

The resource block group may include one or more consecutive resourceblock according to the number of resource blocks included in a subframe.

The number of the resource block group set may correspond with thenumber of resource block included in the resource block group.

The number of resource blocks included in the resource block group setmay correspond with the number of resource block group.

In another aspect of the present invention, provided herein is a methodfor transmitting resource allocation information in mobile communicationsystem, the method including: constructing a control channel includingfirst information which indicates resource allocation type and secondinformation which is a bitmap indicating whether or not to allocate atleast part of resource blocks included in a subframe according to theresource allocation type; transmitting the control channel to ascheduled User Equipment; and transmitting data associated with thecontrol channel to the scheduled User Equipment.

The resource allocation type may indicate at least one of a groupscheduling type and a part-bitmap scheduling type.

The bitmap may indicate a resource block that is allocated to thescheduled User Equipment among one or more resource block included in aresource block group set, in a case that the resource allocation type isthe part-bitmap scheduling type.

The resource block group set may include one or more resource blockgroup.

The resource block group may include one or more consecutive resourceblock.

The control channel may further include third information whichindicates one among one or more resource block group set.

The bitmap may indicate a resource block group that is allocated to thescheduled User Equipment, in a case that the resource allocation type isthe group scheduling type.

In another aspect of the present invention, provided herein is a methodfor receiving resource allocation information in mobile communicationsystem, the method including: receiving information of virtual resourceblock which comprises a part of each of one or more resource block in asubframe; identifying allocated resource block from the information ofvirtual resource block; and receiving data using at least part of theallocated resource block according to the information of virtualresource block.

The information of virtual resource block may include information of theone or more resource block and information which indicates one or moreamong one or more virtual resource block comprised by the one or moreresource block.

The information of virtual resource block may include information of thenumber of the one or more resource block and information of the numberof one or more virtual resource block comprised by the one or moreresource block and information which indicates one or more among the oneor more virtual resource block.

Advantageous Effects

By applying a radio resource allocation method and the construction andthe transmission/reception method of resource allocation informationdisclosed in the present specification, a FSS method and a FDS methodare efficiently combined so as to perform scheduling.

By applying the radio resource allocation method and the constructionand the transmission method of the resource allocation informationdisclosed in the present specification, it is possible to reduce thenumber of bits for transmitting the resource allocation information.

In addition, by using a DVRB construction method disclosed in thepresent specification, it is possible to randomize interference betweencells for transmission of data to user equipments so as to optimizesystem efficiency.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 is a view illustrating a scheduling resource block unit;

FIG. 2 is a view illustrating an example of a group scheduling methodusing a localized virtual resource block (LVRB);

FIG. 3 is a view illustrating an example of a part-bitmap schedulingmethod using a LVRB according to an embodiment of the present invention;

FIG. 4 is a view illustrating an example of a part-bitmap schedulinginformation construction method using a LVRB according to an embodimentof the present invention;

FIG. 5 is a view illustrating an example of a method for constructing adistributed virtual resource block (DVRB) according to an embodiment ofthe present invention;

FIG. 6 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toan embodiment of the present invention;

FIG. 7 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toan embodiment of the present invention;

FIG. 8 is a view illustrating an example of a method for constructing aDVRB according to another embodiment of the present invention;

FIG. 9 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toanother embodiment of the present invention;

FIG. 10 is a view illustrating an example of a method for constructingdifferent DVRBs with respect to cells according to an embodiment of thepresent invention;

FIG. 11 is a view illustrating an example of a physical resource block(PRB) selection method used for transmission of different DVRBs withrespect to cells according to an embodiment of the present invention;and

FIG. 12 is a view illustrating a method for multiplexing transmissionusing a DVRB and transmission using a LVRB in a subframe andtransmitting the multiplexed signal according to an embodiment of thepresent invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 is a view illustrating a scheduling resource block unit.

In a mobile communication system, an uplink/downlink data packet istransmitted in the unit of a subframe and a subframe may be defined by apredetermined time period including a plurality of OFDM symbols. In thepresent specification, the following terms are defined for convenienceof description of technology.

A resource element (RE) is a smallest frequency-time unit in which amodulation symbol of data or control channel is mapped. If a signal istransmitted via M subcarriers in an OFDM symbol and N OFDM symbols in asubframe, M×N REs may exist in the subframe.

A physical resource block (PRB) is a frequency-time resource unit fortransmitting data. In general, a PRB is composed of consecutive RES in afrequency-time domain and a plurality of PRBs are defined in a subframe.

A virtual resource block (VRB) is a virtual resource unit fortransmitting data. In general, the number of RBs included in a VRB isequal to the number of REs included in a PRB. In actual datatransmission, a VRB may be mapped to a PRB or a VRB may be mapped toparts of a plurality of PRBs.

A localized virtual resource block (LVRB) is a type of VRB. A LVRB ismapped to a PRB, and PRBs to which different LVRBs are not mapped to asame PRB. The LVRB may be interpreted as the PRB. Here, a PRB to whichthe LVRB is mapped may be called a PRB for a LVRB.

A distributed virtual resource block (DVRB) is a type of the VRB. A DVRBis mapped to some REs in a plurality of PRBs, and different DVRBs arenot mapped to same REs. Here, a PRB used for a DVRB construction may becalled a PRB for DVRB.

A base station performs scheduling for transmission of downlink data toa specific user equipment or transmission of uplink data from thespecific user equipment to the base station via one or a plurality ofVRBs in a subframe. At this time, the base station should inform theuser equipment of information indicating via which downlink VRB the datais transmitted when the downlink data is transmitted to the specificuser equipment and inform the user equipment of information indicatingvia which uplink VRB the data can be transmitted in order to allow thespecific user equipment to transmit the uplink data.

In an actual system, data transmission using the LVRB and datatransmission using the DVRB may be made together in a subframe. At thistime, in order to prevent the data transmission using the LVRB and thedata transmission using the DVRB from colliding in the same RE, it ispreferable that the data transmission using the DVRB and the datatransmission using the LVRB use different PRBs in a subframe.

In other words, the PRBs in the subframe may be divided into PRBs forthe LVRB and PRBs for the DVRB as described above. In the case that thedata transmission using the LVRB and the data transmission using theDVRB are made together in a subframe, the specific user equipment may beinformed of whether the VRB used for transmission/reception of theuplink/downlink data is the LVRB or the DVRB.

Hereinafter, first, a data transmission method using a LVRB and a methodfor transmitting scheduling information will be described.

If N_(LVRB) LVRBs exist in a subframe, a base station performsuplink/downlink scheduling according to the data transmission methodusing the LVRB by using the N_(LVRB) LVRBs with respect to at least oneuser equipment.

Then, N_(LVRB)-bit bitmap information is transmitted to the userequipment so as to inform the user equipment of information indicatingvia which LVRB the downlink data is transmitted or informationindicating via which LVRB the uplink data can be transmitted. That is,each bit in the N_(LVRB)-bit bitmap information represents datatransmission information with respect to each of the N_(LVRB) LVRBs.

For example, in the N_(LVRB)-bit bitmap information, with respect to theLVRB used for transmission/reception of the uplink/downlink data to/fromthe user equipment, a bit for the LVRB is set to 1 and, with respect tothe LVRB which is not used for transmission/reception of theuplink/downlink data to/from the user equipment, a bit for the LVRB isset to 0. The user equipment which receives the N_(LVRB)-bit bitmapinformation constructed by this method can receive the downlink data ortransmit the uplink data using the LVRB which is set to 1 in theN_(LVRB)-bit bitmap information.

FIG. 2 is a view illustrating an example of a group scheduling methodusing a LVRB.

In a case that the number of LVRBs which exist in a subframe is large,the base station uses too many downlink resources for informing the userequipment of the N_(LVRB)-bits bitmap information. At this time,N_(LVRB) LVRBs are divided into N_(group) LVRB groups such that data istransmitted/received in the unit of a LVRB group. Thus, it is possibleto reduce number of downlink resources which are used at the time of thetransmission of the bitmap information.

That is, in the transmission of the data in the unit of the LVRB group,the base station informs the user equipment of the N_(group)-bit bitmapinformation of the N_(group) LVRB groups instead of the N_(LVRB)-bitbitmap information of the LVRBs (N_(group)=N_(LVRB)).

In addition, if the LVRB is used for transmitting/receiving the data bythe PSS method, it is advantageous that the data is transmitted usingconsecutive subcarriers in a frequency domain in the FSS method.Accordingly, each of the LVRB groups is composed of consecutive PRBs inthe frequency domain. This method is called a group scheduling method inthe present invention.

In FIG. 2, a subframe is composed of 48 PRBs and each PRB is mapped to aLVRB. At this time, three LVRBs are combined to construct a LVRB groupsuch that 16 LVRB groups exist in the subframe. Accordingly, the basestation informs a specific user equipment of an area in which downlinkdata is transmitted to the specific user equipment or an area in whichthe specific user equipment can transmit uplink data, via 16-bit bitmapinformation.

However, if the data is transmitted in the unit of the LVRB group,N_(group) LVRBs are used for even transmission of a small amount of datasuch that a frequency-time resource is wasted. If consecutive N_(group)LVRBs in the frequency domain become a basic data transmission unit, itis difficult to efficiently perform data transmission using the FDSmethod.

Accordingly, in the present embodiment, in order to reduce the resourcesnecessary for informing the user equipment of the LVRB via which thedata is transmitted while the data can be transmitted in the unit of theLVRB instead of the unit of the LVRB group, a method for informing theuser equipment whether or not the data can be transmitted via the LVRBs,via the LVRB-unit bitmap information only with respect to a part of allthe LVRBs in the subframe is suggested.

The user equipment which is allocated with the LVRB fortransmission/reception of the data can transmit/receive the data via theLVRBs belonging to a LVRB set with respect to a subframe. This method iscalled a part-bitmap scheduling method in the present invention.

FIG. 3 is a view illustrating an example of a part-bitmap schedulingmethod using a LVRB according to an embodiment of the present invention.

In the present embodiment, when N_(LVRB) LVRBs exist in a subframe, apart of all the LVRBs in the subframe is defined as a LVRB set. In otherwords, N_(LVRB) _(—) _(part) LVRB sets (N_(LVRB) _(—) _(part)<N_(LVRB))are previously defined.

Here, the LVRB set may be constructed by various methods. At an upperside of FIG. 3, a LVRB group or a LVRB set may be defined in associationwith a set construction method and a group construction method forapplying the group scheduling method shown as an example. If the LVRBset is defined in consideration of the LVRB group construction methodfor applying the group scheduling method, the group scheduling methodand the part-bitmap scheduling method can be used to be compatible witheach other. Thus, flexible scheduling is possible. Hereinafter, twomethods for constructing the LVRB set in consideration of the LVRB groupconstruction method will be described as embodiments.

In a first method, like the part-bitmap scheduling method 1 of FIG. 3, aLVRB set is defined so as to include a plurality of LVRB groups used forthe group scheduling method, and more particularly, inconsecutive LVRBgroups in the frequency domain. According to this method, a plurality ofLVRBs in the LVRB group may be allocated to a user equipment.Accordingly, all the LVRBs in the LVRB group can be used by thepart-bitmap scheduling for a small number of user equipments.

In a second method, a LVRB set is composed of LVRBs which are separatedfrom each other at a predetermined PRE interval in the frequency domain.Like the part-bitmap scheduling method 2 of FIG. 3, a LVRB set may beconstructed so as to include a LVRB belonging to each LVRB group. Thismethod is advantageous in that, when the part-bitmap scheduling methodis used for the data transmission using the FDS method, the data can betransmitted/received to/from a user equipment by only the LVRBs whichare separated from each other in the frequency domain.

In the part-bitmap scheduling method, the LVRB sets may be constructedby the two above-described methods, which are only exemplary. The LVRBsets may be constructed by various methods.

FIG. 4 is a view illustrating an example of a part-bitmap schedulinginformation construction method using a LVRB according to an embodimentof the present invention.

The scheduling information construction examples shown in FIG. 4represent a scheduling information construction of a user equipment andmore particularly a scheduling information construction which can betransmitted to a user equipment which is scheduled using the LVRB.

In the present embodiment, as described above, it is assumed that, whenN_(LVRB) LVRBs exist in a subframe, a part of all the LVRBs in asubframe are defined as a LVRB set.

At an upper side of FIG. 4, a scheduling information construction methodwhen the LVRB set is defined so as to perform scheduling is shown. Asshown at the upper side of FIG. 4, the base station may inform the userequipments of information indicating via which LVRB the user equipmentsreceive or transmit the data, using LVRB set information 40 indicatingto which LVRB set a bitmap corresponds and N_(LVRB) _(—) _(part)-bitbitmap information 41 indicating whether or not data can be transmittedvia the LVRBs in the LVRB set.

It is assumed that the user equipment which receives schedulinginformation knows that the LVRB is allocated via broadcastinginformation or scheduling information. Accordingly, the schedulinginformation shown at the upper side of FIG. 4 is received such that itcan be checked in which set an available LVRB is included, using theLVRB set information 40. Subsequently, the N_(LVRB) _(—) _(part)-bitbitmap 41 is received such that it can be checked which LVRB in the setchecked via the LVRB set information 40 is available.

At a lower side of FIG. 4, as described above, the schedulinginformation construction method when a LVRB group and a LVRB set areassociated with each other such that the group scheduling method and thepart-bitmap scheduling method can be used to be compatible with eachother is shown.

As shown at the lower side of FIG. 4, the base station informs the userequipments of information indicating via which LVRB the user equipmentsreceive or transmit the data, via group/set indicating information 42indicating whether bitmap information is bitmap information for the LVRBgroup or bitmap information for LVRB set, LVRB set information 43indicating to which LVRB set the bitmap corresponds when the bitmapinformation is the bitmap information for the LVRB set, andN_(bitmap)-bit bitmap information 44 indicating whether or not data forthe LVRB group can be transmitted or whether or not data for LVRBs inthe LVRB set can be transmitted.

It is assumed that the user equipment which receives the schedulinginformation knows that the LVRB is allocated via broadcastinginformation or scheduling information. The user equipment receives thescheduling information shown at the lower side of FIG. 4 so as to checkwhether subsequent bitmap information is bitmap information for the LVRBgroup or bitmap information for the LVRBs in the set via the group/setindicating information.

If the group/set indicating information 42 indicates the set, it can bechecked which set an available LVRB is included via the LVRB setinformation 43. Subsequently, the N_(bitmap)-bit bitmap information 44is received such that it can be checked which LVRB in the set checkedvia the LVRB set information 43 is available. Similarly, if thegroup/set indicating information 42 indicates the group, it can bechecked which LVRB is available via the N_(bitmap)-bit bitmapinformation 44.

As another embodiment of the case where the group scheduling method andthe part-bitmap scheduling method can be used to be compatible with eachother, as shown at the lower side of FIG. 4, the group/set indicatinginformation 42 are not transmitted as separate bit information and maybe transmitted as an element of the LVRB set information 40 describedwith reference to the embodiment shown at the upper side of FIG. 4. Forexample, if three LVRB sets exist, 00 indicates that the bitmapinformation is the bitmap information for the LVRB group and 01, 10 and11 are set to indicate the LVRB set information such that it isindicated that the bitmap information is the bitmap information for theLVRB set. That is, 01, 10 and 11 may be set to indicate the LVRB set 1,the LVRB set 2 and the LVRB set 3, respectively.

As described above, if the LVRB group and the LVRB set are associatedwith each other, it is possible to freely allocate data. In particular,at this time, it is preferable that N_(bitmap)=N_(LVRB) _(—)_(part)=N_(group) is satisfied. If N_(bitmap)=N_(LVRB) _(—)_(part)=N_(group) is satisfied, bitmap information having apredetermined or fixed size may be used.

Among the data transmission methods, in the FSS method, since the datais transmitted using the consecutive subcarriers in the frequencydomain, it is more efficient that the data is transmitted using theLVRB. If the present embodiment is used, the amount of schedulinginformation can be reduced and scheduling can be performed by acombination of the FSS method and the FDS method. Accordingly, atransmission resource can be more efficiently used.

Up to now, the data transmission method using the LVRB and the methodfor transmitting the scheduling information were described.

Hereinafter, the data transmission method using the DVRB and the methodfor transmitting the scheduling information will be described.

The data transmission using the FDS method via a small number of VRBscannot be efficiently performed by the group scheduling method or thepart-bitmap scheduling method. For example, in a case where thepart-bitmap scheduling method is applied when a data packet istransmitted via a VRB, the data packet can be transmitted via only asingle LVRB. Accordingly, the data packet is transmitted by theconsecutive subcarriers in the frequency domain such that a frequencydiversity gain cannot be obtained. Thus, in the present embodiment, twomethods for efficiently performing the data transmission using the FDSmethod are suggested.

FIG. 5 is a view illustrating an example of a method for constructing aDVRB according to an embodiment of the present invention.

In the present embodiment, REs included in N_(DVRB) PRBs for the DVRBare combined so as to construct N_(DVRB) DVRBs. In this method, a DVRBis constructed so as to include a specific amount of REs in each PRBbelonging to N_(DVRB) PRBs. FIG. 5 shows an example of combining REsincluded in four PRBs for the DVRB so as to construct four DVRBs. Thatis, in FIG. 5, a DVRB is constructed so as to include five REs in eachPRB belonging to four PRBs for the DVRB.

At this time, when the data packet is transmitted via one or a pluralityof DVRBs, a frequency diversity gain can be obtained. The base stationcan combine a predetermined number of PRBs and construct a DVRB viawhich data can be transmitted/received to/from a specific userequipment, for the FDS transmission/reception method. The userequipments may be Informed of the PRB for the DVRB which will be usedfor data transmission/reception using the DVRB, how the DVRBs areconstructed in the PRBs for the DVRB, and via which of DVRBs the data istransmitted/received.

FIG. 6 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toan embodiment of the present invention.

As described with reference to FIG. 5, scheduling information, which canbe transmitted from the base station when a method for combining REsincluded in N_(DVRB) PRBs for the DVRB so as to construct the N_(DVRB)DVRBs is used, will be described. In this case, in the presentinvention, when the base station transmits/receives the data to/from anyuser equipment via the DVRB in any subframe, a method for informing theuser equipment of the following information is suggested. That is, FIG.6 shows scheduling information of a user equipment.

First, the user equipment is informed of PRB information for the DVRB 60including the REs constructing the DVRB via which the data istransmitted/received to/from the user equipment. For example, the PRBinformation for the DVRB 60 may become index information of PRBs orbitmap information for identifying the PRBs.

The base station may indirectly inform the user equipment how the DVRBsare constructed via the PRB information for the DVRB 60 including theREs constructing the DVRB. For example, if the base station informs theuser equipment of three PRBs used for transmission/reception of the datato/from the user equipment, the user equipment estimates that the RBs ineach PRB are divided into three groups and three DVRBs to which a REgroup is mapped are defined in three PRBs.

In particular, it is assumed that, when the indexes of the PRBs areinformed, N_(max) PRBs can be used in the DVRB construction as amaximum. At this time, if N_(used) (smaller than N_(max)) PRBs are used,the indexes of the PRBs actually used are repeatedly placed at theremaining PRB index bits excluding bits indicating the indexes of theN_(used) PRBs. If the indexes of the PRBs actually used are repeatedlyinformed using the remaining bits, the user equipment may be informed ofhow many PRBs are used without separate information.

In other words, although the base station does not inform the userequipment of information indicating how many PRBs are used, the userequipment can estimate how many PRBs are used. For example, if therepeated indexes of the PRBs are not present, it may be estimated thatN_(max) PRBs are used. It the repeated indexes of the PRBs are present,it is checked whether the indexes of N_(repeat) PRBs are repeated suchthat it is estimated that N_(used) PRBs are actually used byN_(used)=N_(max)−N_(repeat).

In more detail, the indexes of the PRBs actually used are collectivelyplaced at N_(used) PRB index bits in a start part or an end part of thePRB information for the DVRB 60. If the indexes of the PRBs actuallyused are collectively transmitted to the start part or the end part ofthe PRB information 60, the receiver easily distinguishes between theindexes of the PRBs actually used and the indexes of the repeated PRBssuch that the scheduling information can be more efficientlytransmitted/received.

In addition, in a case that the bitmap information or the indexes of thePRBs for the DVRB which will be used for the DVRB transmission isinformed, the bitmap information or the indexes of the PRBs which isconstructed with respect to some PRB sets may be informed instead of thebitmap or the indexes of all the PRBs which exist in a system band, inorder to reduce a necessary bit number.

In other words, if the indexes of the PRBs are informed, the indexesallocated to the PRBs for the DVRB belonging to a specific set or groupamong the PRBs used in the DVRB construction or the PRBs for the DVRBused in the DVRB construction may be informed, instead of the indexesallocated to all the PRBs included in a subframe.

Even when the bitmap information is informed, the indexes allocated tothe PRBs for the DVRB belonging to a specific set or group among thePRBs used in the DVRB construction or the PRBs for the DVRB used in theDVRB construction may be informed, instead of the indexes allocated toall the PRBs included in a subframe.

FIG. 7 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toan embodiment of the present invention.

In particular, in a case that the indexes of the PRBs constructing aDVRB (or information of any format, which can sequentially indicate theindexes of the PRBs) are informed, the user equipment may be informed ofwhich part of the PRBs is actually allocated to the user equipment via asequence indicating a PRB index in a scheduling command transmitted tothe user equipment.

For example, as shown in FIG. 7, in a case of N_(D)=2, the PRBs aredivided into two groups in view of time and the two groups are allocatedto different DVRBs. A rule that the index of a first PRB grouptransmitted via a scheduling command indicates an early (or late) partand the index of a second PRB group indicates a late (or early) part inview of time may be decided.

Similarly, even when the PRBs are divided into two groups in view of thefrequency or the like, a predefined sequence of parts of a PRB may bemapped to a PRB index sequence of the scheduling command. This isapplicable to a case that N_(D) is larger than 2. In this case, inparticular, in a case that only one DVRB is restricted to be allocatedto one user equipment, information for scheduling the allocation of anactual physical time-frequency resource of the DVRB to the userequipment may be constructed by only the indexes of the PRBsconstructing the DVRB (or information of any format which cansequentially indicate the indexes of the PRBs).

DVRB information 61 indicating DVRBs via which data is actuallytransmitted/received to/from the user equipment, among the DVRBs whichare estimated via the PRB information for the DVRB 60, is informedtogether with the PRB information for the DVRB 60. The DVRB informationmay be constructed in a form directly identifying the DVRBs. Forexample, the DVRB information may become index information of the DVRBsvia which the data is transmitted/received to/from the user equipment.

The DVRB information may be constructed so as to identify first DVRBinformation and information indicating via how many DVRB the data istransmitted/received to/from the user equipment. In order to inform thefirst DVRB information, it is assumed that the indexes are allocated tothe DVRBs according to a predetermined rule. Information about thenumber of DVRBs via which the data is transmitted/received may bereplaced with the amounts of REs used for transmission/reception of thedata.

For example, it is assumed that scheduling is performed according to theDVRB construction method shown in FIG. 5. That is, it is assumed thatfour DVRBs are constructed using a total of four PRBs and thetransmission/reception of the data to/from the user equipment isperformed via the DVRB having a DVRB index of 4.

In this case, the PRB information for the DVRB 60 may become the indexinformation of the PRBs and the bitmap information for identifying thePRBs as described above. If the index information is transmitted, theindex information allocated to first, second, fifth and seventh PRBs ofFIG. 5 is transmitted. At this time, as described above, when it isassumed that N_(max)=66 PRBs can be used as a maximum, the index of anyPRB or a specific PRB of the first, second, fifth, and seventh PRBs maybe repeated and transmitted using the remaining bits of two remainingPRB indexes. If the bitmap information is transmitted, the bitmap bitsof the first, second, fifth and the seventh PRBs are, for example, setto 1 and are transmitted such that it is indicated that thetransmission/reception of the data is performed.

In a case that the DVRB information 61 is constructed in a manner ofdirectly indicating the DVRBs, information corresponding to the DVRBindex information of 4 is transmitted. In a case that the DVRBinformation 61 is constructed by the first DVRB information among theDVRBs via which the data is transmitted/received to/from the userequipment and the information for informing the user equipment of viahow many DVRBs the data is transmitted/received, informationcorresponding to one DVRB and the DVRB index information of 4 istransmitted.

A base station scheduler freely selects PRBs in each subframe andconstructs the DVRB using the above-described method such that the FDStransmission method and the FSS transmission method are freelymultiplexed.

FIG. 8 is a view illustrating an example of a method for constructing aDVRB according to another embodiment of the present invention.

In the present embodiment, as shown in FIG. 8, the construction of thePRBs used for DVRB transmission and the DVRB using the PRBs are actuallydecided according to the number of PRBs for the DVRB used for thetransmission/reception of the DVRB method and the numerals are allocatedto the decided DVRBs according to a predetermined rule.

For example, at an upper side of FIG. 8, if the number of PRBs for DVRBused for the DVRB transmission/reception is two, the PRBs used for theDVRB transmission are the first and fifth PRBs and the RES in each PRBare divided into two groups and the indexes 1 and 2 are sequentiallyallocated to the two groups. The RE groups, to which the same index isallocated in each PRB, are combined so as to construct a DVRB.

Similarly, at a lower side of FIG. 8, if the number of PRBs for the DVRBused for the DVRB transmission/reception is 4, the PRBs used for theDVRB transmission are the first, third, fifth and seventh PRBs and theREs in each PRB are divided into four groups and the indexes 1, 2, 3 and4 are sequentially allocated to the four groups. The RE groups, to whichthe same index is allocated in each PRB, are combined so as to constructa DVRB.

FIG. 9 is a view illustrating an example of a scheduling informationconstruction method with respect to scheduling using a DVRB according toanother embodiment of the present invention.

As described with respect to FIG. 8, in a case where a method fordeciding the PRB and DVRB construction used for the DVRBtransmission/reception method according to the total number of PRBs forthe DVRB used for the DVRB transmission/reception method in a subframeis used, the scheduling information which can be transmitted by the basestation will be described. In this case, in the present embodiment, in acase that the base station transmits/receives the data to/from any userequipment in any subframe, a method for informing the user equipment ofthe following information is suggested. That is, FIG. 9 shows thescheduling information for a user equipment.

The base station informs the user equipment of the total number of PRBsfor the DVRB 80 used for the DVRB transmission/reception method in anysubframe. Here, the total number of PRBs for the DVRB may be replacedwith the total number of DVRBs. As described above, if the total numberof PRBs for DVRB 80 used for the DVRB transmission/reception method isknown, the user equipment can know the construction of the PRBs used forthe DVRB transmission and the DVRB using the PRBs.

The DVRB information used for the transmission/reception of the datato/from the user equipment is transmitted. If a rule that the data istransmitted/received via the DVRBs having the consecutive numerals isapplied to a user equipment, the base station informs the user equipmentwhich transmits/receives the data via the DVRBs of an index of a startDVRB 81 and the number of DVRB 82 so as to inform the user equipment ofthe DVRBs via which the data is transmitted/received. Here, the numberof DVRBs 82 may be replaced with the amount of REs.

For example, it is assumed that the scheduling is performed according tothe DVRB construction method shown at the lower side of FIG. 8. That is,if the number of PRBs for the DVRB used for the DVRBtransmission/reception method is 4, the PRBs used for the DVRBtransmission are first, third, fifth and seventh PRBs, the REs in eachPRB are divided into four groups and the indexes 1, 2, 3 and 4 aresequentially allocated to the tour groups. It is assumed that the REgroups, to which the same index is allocated in each PRB, are combinedso as to construct a DVRB.

In this case, the total number of PRBs 80 used for the DVRBtransmission/reception method is 4. A receiver receives the total numberof PRBs for the DVRB 80 of 4, which is used for the DVRBtransmission/reception method, and knows that the DVRB is constructed asshown at the lower side in FIG. 8. In the case that the DVRB informationis constructed in a manner of directly indicating the DVRBs, theinformation corresponding to the DVRB index information of 4 istransmitted. When the start DVRB index 81 and the number of DVRBs 82 aretransmitted as the DVRBs via which the data is transmitted/receivedto/from the user equipment, the information corresponding to a DVRB andthe DVRB index information of 4 is transmitted. The receiver receivesthe information and knows that the data is transmitted/received using aDVRB having the DVRB index of 4.

By the above-described method, a base station scheduler freely selectsPRBs in each subframe and constructs the DVRB such that the FDStransmission method and the FSS transmission method are freelymultiplexed.

In more detail, in the above-described embodiment, the user equipmentswhich transmit/receive the data via the DVRBs may be informed of thetotal number of PRBs for the DVRB 80 used for the DVRBtransmission/reception method via a control channel for transmitting thescheduling information to the user equipments. When the total number ofPRBs for the DVRB 80 used for the DVRB transmission/reception method istransmitted to the user equipments which transmit/receive the data viathe DVRBs, bits for transmitting this information do not need to beadded.

The user equipments cannot know whether the group scheduling informationor bitmap scheduling information is transmitted via the LVRB or whetherDVRB scheduling information is transmitted, before decoding and readinga downlink control channel for transmitting the scheduling information.Accordingly, it is efficient that the downlink control channel fortransmitting this information is constructed by applying the sameencoding to the same number of bits, regardless of the schedulingmethod. That is, it is preferable that information indicating whichscheduling method is applied is included in the information bitsindicating the scheduling information and information which should beindicated by the scheduling method is included in the remaining part.

At this time, since the part-bitmap scheduling information or the groupscheduling information via the LVRB indicates the LVRBs via which thedata is transmitted/received by a bitmap method, if the number of LVRBsin the subframe is large, a large bit number is required. For example,in a case that 48 LVRBs are divided into 3 LVRB groups so as toconstruct group scheduling information, 16 bits are necessary forindicating the LVRB group for transmitting/receiving the data. That is,the scheduling information should be transmitted via at least 16 bits.

In the DVRB scheduling method suggested by the present invention, sinceonly a first DVRB index for performing data transmission/reception andthe number of DVRBs via which the data is transmitted/received to/fromthe user equipment are informed, only 12 bits are required as a maximum.Accordingly, since at least 16 bits are required for the schedulinginformation transmission via the LVRB, although the total number of PRBsused for the DVRB transmission/reception method is added, the downlinkresource used for the control channel for transmitting the schedulinginformation is not increased or is decreased.

FIG. 10 is a view illustrating an example of a method for constructingdifferent DVRBs with respect to cells according to an embodiment of thepresent invention.

If a DVRB construction method which is equally defined by every cell isapplied to a cellular system, a probability that the REs in a specificDVRB allocated to the data transmission of a user equipment arecompletely matched to the REs in a specific DVRB allocated to the datatransmission of another user equipment of a neighboring cell is veryhigh. In this case, in particular, in a case that the two userequipments of the neighboring cells having the same DVRB allocated tothe data transmission are close to each other, relatively highinterference may occur compared with other user equipments. Accordingly,in order to avoid the case where the REs in a specific DVRB of one cellare completely matched to the REs in a specific DVRB of another cell,randomization of the REs in the specific DVRB is required.

Accordingly, in the present embodiment, in order to randomize the REsallocated to the DVRBs in different cells, a method for differentlydefining the relative position of the subcarrier, the position of theOFDM symbol or the position of the RE in the PRB for the DVRB in eachcell is suggested.

FIG. 10 shows an example of setting the position for mapping the RE toany DVRB using different interleaving methods in two cells in the unitof an RE. That is, indexes 1 to 20 are allocated to 20 REs included ineach PRB for the DVRB used for the DVRB transmission. Interleaving orshifting is performed with respect to the 20 REs included in each PRBfor the DVRB. The positions of the REs for the RE index varies accordingto the cells.

In other words, although the RE having the same index is allocated tothe DVRB according to the cells, the positions of the physicalsubcarriers or the OFDM symbols may be different from each other. Theinterleaving or shifting rule used at this time can more efficientlyperform randomization if a cell ID is input. In the interleaving orshifting rule, a random sequence may be input together with orindependent of the cell ID.

The interleaving operation or the shifting operation may be performed inthe unit of an RE or the unit of an RE group. For example, theinterleaving operation or the shifting operation may be performed in theunit of an RB belonging to the same subcarrier or the unit of an REbelonging the same OFDM symbol. In addition, the interleaving operationor the shifting operation may be performed over all the PRBs allocatedto the DVRB transmission or some PRBs in a subframe as well as each PRB.

FIG. 11 is a view illustrating an example of a PRB selection method usedfor transmission of different DVRBs with respect to cells according toan embodiment of the present invention.

In the present embodiment, in order to randomize interference betweenneighboring cells for the REs allocated to the DVRB and prevent theinterference between the PRBs allocated to the DVRB from occurringbetween the neighboring cells, a method for changing the selection ofthe PRB for the DVRB allocated to the DVRB transmission in the subframeis provided.

FIG. 11 shows an example of a method for changing the selection of thePRB for the DVRB allocated to the DVRB transmission in the subframe. Forexample, the DVRB is constructed using the first, fourth and seventhPRBs in a cell 1, but the DVRB is constructed using the second, fifthand eighth PRBs in a cell 2 unlike the cell 1.

In order to change the selection of the PRB for the DVRB allocated tothe DVRB transmission in each cell, different shifting or interleavingoperation can be used with respect to the PRB index. In the shifting orinterleaving rule used at this time, for example, a cell ID or apredetermined random sequence may be input, similar to the randomizationof the RE position.

Among the methods for transmitting the data, in the FSS method, sincethe data is transmitted using consecutive subcarriers in the frequencydomain, it is preferable that the data is transmitted using the LVRB.Among the methods for transmitting the data, in the FDS method, it ispreferable that the data is transmitted using the DVRB in order totransmit the data using the inconsecutive subcarriers in the frequencydomain.

FIG. 12 is a view illustrating a method for multiplexing transmissionusing a DVRB and transmission using a LVRB in a subframe andtransmitting the multiplexed signal according to an embodiment of thepresent invention.

As described above, it is preferable that the transmission using theDVRB and the transmission using the LVRB are multiplexed in a subframe.In particular, a method for deciding the position and the number of PRBs(hereinafter, referred to as DPRB) used for the DVRB transmission methodby the number of DVRBs transmitted actually similar to theabove-described method and directly/indirectly informing the userequipments in the cell of this information is applied to the DVRBtransmission. If scheduling using the LVRB group is applied before theLVRB scheduling, a part of PRBs constructing any LVRB group in anysubframe may be allocated to the DVRB transmission.

For example, referring to FIG. 12, 48 PRBs exist in a subframe and threePRBs are combined so as to construct a LVRB group. Thus, 16 LVRB groupsexist. At this time, it PRBs represented by “*” are allocated to theDVRB, second, sixth, tenth and fifteenth LVRB groups collide with theDVRB transmission at the time of LVRB group transmission.

Accordingly, in the present embodiment, in a case that a part of anyLVRB group is used for the DVRB transmission to any user equipment, amethod for transmitting the data transmitted to another user equipmentvia the LVRB group using only the LVRB which is not used for the DVRBtransmission is suggested. That is, in the example of FIG. 12, if thedata is transmitted to any user equipment via the second LVRB group bythe LVRB group scheduling, the LVRB transmission can be performed withrespect to the user equipment via two remaining PRBs excluding the firstPRB used for the DVRB transmission among three PRBs in the second LVRBgroup, that is, the PRBs represented by “#”.

In a case that the PRB used for the DVRB transmission among the PRBsconstructing the LVRB group is present when the scheduling informationindicating that the data is received via a specific LVRB group isreceived, the user equipment determines that the data is not receivedvia the PRB and receives the data which is transmitted via the LVRB withrespect to the remaining PRBs.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

That is, the present patent is not limited to the embodiments describedherein and should be interpreted to have the widest range according tothe principles and features disclosed herein.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a mobile communication system, acellular mobile communication system and a cellular multiplexing carriersystem.

What is claimed is:
 1. A method for a user equipment (UE) operating in awireless communication system, the method comprising: receiving, by theUE, control information including first information and secondinformation, wherein the first information indicates one of two resourceallocation types and the second information includes a bitmap indicatingresource allocation; and receiving, by the UE, the data using one ormore resource blocks (RBs) allocated by the control information,wherein, if the first information indicates a first resource allocationtype of the two resource allocation types, a first bit value of thebitmap indicates whether a corresponding resource block group (RBG) isallocated or not; if the first information indicates a second resourceallocation type of the two resource allocation types, the controlinformation includes third information indicating one of N RB sets, anda second bit value of the bitmap indicates whether a corresponding RB isallocated or not in the indicated RB set comprising a plurality of RBGs,a size of RBG is N consecutive RBs, and N is an integer equal to orgreater than
 2. 2. The method according to claim 1, wherein theindicated RB set comprises every Nth RBG starting from a predeterminedRBG.
 3. The method according to claim 1, wherein the indicated RB setcomprising a plurality of RBGs, in which neighboring RBGs are notconsecutive in a frequency region.
 4. The method according to claim 1,wherein indicated RB set comprises a plurality of RBGs, in whichneighboring RBGs are spaced by N−1 RBG(s).
 5. The method according toclaim 1, wherein the first bit value of the bitmap indicates whether acorresponding resource block group (RBG) is allocated or not inconsecutive RBGs.
 6. The method according to claim 1, wherein a numberof RBs in each RBG depends on a total number of RBs in a subframe. 7.The method according to claim 1, wherein a number of the RB sets is thesame as a number of RBs in each RBG.
 8. A user equipment (UE) operatingin a wireless communication system, the UE comprising: a radio frequency(RF) module; and a processor configured to control the RF module,wherein the processor is configured to receive control informationincluding first information and second information, wherein the firstinformation indicates one of two resource allocation types and thesecond information includes a bitmap indicating resource allocation, andto receive the data using one or more resource blocks (RBs) allocated bythe control information, wherein, if the first information indicates afirst resource allocation type of the two resource allocation types, afirst bit value of the bitmap indicates whether a corresponding resourceblock group (RBG) is allocated or not; if the first informationindicates a second resource allocation type of the two resourceallocation types, the control information includes third informationindicating one of N RB sets, and a second bit value of the bitmapindicates whether a corresponding RB is allocated or not in theindicated RB set comprising a plurality of RBGs, a size of RBG is Nconsecutive RBs, and N is an integer equal to or greater than
 2. 9. TheUE according to claim 8, wherein the indicated RB set comprises everyN_(th) RBG starting from a predetermined RBG.
 10. The UE according toclaim 8, wherein the indicated RB set comprising a plurality of RBGs, inwhich neighboring RBGs are not consecutive in a frequency region. 11.The UE according to claim 8, wherein indicated RB set comprises aplurality of RBGs, in which neighboring RBGs are spaced by N−1 RBG(s).12. The UE according to claim 8, wherein the first bit value of thebitmap indicates whether a corresponding resource block group (RBG) isallocated or not in consecutive RBGs.
 13. The UE according to claim 8,wherein a number of RBs in each RBG depends on a total number of RBs ina subframe.
 14. The UE according to claim 8, wherein a number of the RBsets is the same as a number of RBs in each RBG.